Building Renewables for a Net Zero Future
Tauhara Geothermal Power Station
United Civil completed civil works for Contact Energy’s $924million Tauhara Geothermal Power Station in Taupō, one of the world’s largest single shaft geothermal plants. The project offsets the equivalent of over 500,000 tonnes of CO₂ each year and plays an important role in advancing New Zealand towards a Net Zero future.
United Civil was commissioned by Contact Energy to deliver various civil works for the Tauhara Geothermal Power Station development in Taupō. With an investment of $924 million and a generation capacity of 174 MW, Tauhara is home to one of the largest single shaft geothermal turbines in the world. By offsetting fossil fuel generation, this project is expected to displace the equivalent of more than 500,000tCO₂ annually (which has the same effect of removing over 220,000 cars from New Zealand’s roads!).
The civil scope included 5,500 m³ of structural concrete for the centrally located separator station, the geothermal water pump station, dump valves, atmospheric flash tanks, steam vent station, acid storage and dosing facilities, and the installation of foundations for four main steam transmission lines. Our work also covered several kilometres of watermains and firefighting mains, together with a 145,000 m³ double lined geothermal holding pond to contain any unplanned outflow.
The project commenced during the height of the COVID-19 pandemic, presenting major logistical challenges in securing plant, specialist labour and critical materials. To manage this uncertainty and fairly allocate risk, a bespoke commercial agreement was developed with the client. We mobilised a core team from Whangārei to Taupō and coordinated with local subcontractors to maintain quality standards despite the scale and complexity of the programme. Strong supplier relationships proved critical, particularly in sourcing construction materials such as reinforcing steel.
United Civil established a precast facility on site, which reduced transport costs, improved quality control and accelerated programme lead times. Innovative thinking also enabled two local concrete suppliers to work together to provide sufficient capacity to supply large concrete pours, some up to 15–16 hours in duration.
This project was completed on time and to a very high standard and without any lost-time safety incident.
Key features and innovations
- 5,500 m³ of structural concrete for a centrally located separator station
- Several kilometres of watermains and firefighting mains
- 145,000m³ double-lined geothermal holding pond to receive any unplanned geothermal outflow
- 5,000m of HV and LV duct trenching
- Construction of a wet well using a mix of precast and cast in-situ elements
- Zero lost time health and safety incidents